#include    <fstream>
#include    <vector>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

#define ARRAY_MAX 100000

int N, M, X, Y, Connected, Next;

vector <int> Edge[ARRAY_MAX];
bool Visited[ARRAY_MAX];

void DFS(int Node) {
    Visited[Node] = 1;

    for (unsigned i = 0; i < Edge[Node].size(); i++) {
        Next = Edge[Node][i];

        if (!Visited[Next])
            DFS(Next);
    }
}

void Read() {
    fin >> N >> M;

    for (int i = 1; i <= M; i++) {
        fin >> X >> Y;

        Edge[X].push_back(Y);
        Edge[Y].push_back(X);
    }
}

void Write() {
    for (int i = 1; i <= N; i++)
        if (!Visited[i]) {
            Connected++;

            DFS(i);
        }

    fout << Connected;
}

int main() {
    Read();
    Write();
}